1. Field of the Invention
The present invention relates to a data retrieving technique, and more particularly to a data retrieving method and apparatus for retrieving data and narrowing the range of retrieved data, while referring to a displayed agreement or satisfaction degree relative to a given retrieving condition.
2. Description of the Related Art
In a conventional data retrieving process, numerical values of an item to be retrieved are designated as retrieving conditions. For example, consider a database file storing data of at least prices and weights. In retrieving high prices and light weights from such a database file, a retrieving condition equation "Price&gt;100 & Weight.gtoreq.50" for example is used for the data retrieval. In this case, retrieved data falls within the price range higher than "100" and within the weight range equal to or smaller than "50". If the range of retrieved data is to be further narrowed, a new retrieving condition equation is used which is assigned different values determined with reference to the first data retrieval results. If more desired data is to be selected from the retrieved data, a synthetic decision for such selection has been prepossessed by the user.
The publication of JP-A-2-87275 describes that a retrieving condition equation having a question inclusive of fuzzy values is transformed into a new retrieving condition equation assigned the same attributes as those stored in an index unit. A list of the attributes are displayed on a display screen, allowing a user to designate the retrieving conditions by using attribute terms.
With the above-described conventional technique, if a user cannot determine easily the numerical values to be assigned to the retrieving condition equation, the user determines from the sixth sense the range of data to be retrieved. The process of narrowing the range of retrieved data, including a step of checking the retrieved results, a step of changing the retrieving condition equation, and a step of retrieving data again, has been repeated heretofore in many cases. Data retrieval through designation of rough or fuzzy retrieving conditions was impossible.
In determining the properness of retrieved results, only a user's sixth sense has been relied upon. It is therefore difficult to again perform the data retrieval by changing the retrieving condition equation, and to make an objective judgment. Furthermore, there is no practical means for synthetically evaluating retrieved results or weight-added retrieved results, so that determining the range of data to be retrieved has been relied upon the sixth sense or intuition.